The present invention relates to a device for a machine of displacement type, comprising: a) a non-rotatable housing which surrounds two mutually movable parts, b) a first part which with its outer circumference is controllably rotationally movable along inside wall of the housing, c) a second part which is controllably movable relative to inner circumferential face of the first part, and d) at least one inlet aperture and at least one outlet aperture associated with a wall of the housing.
Further, the invention relates, in a first aspect, to a controlling gear arrangement to cause continuous, mutually variable movement of a first part and a second part which are co-axial, and wherein the first and second parts are in operational co-operation with a main drive shaft, and in a second aspect relates to a controlling gear arrangement in operational co-operation with machine device to control two continuously rotating, mutually movable functional parts in the machine device, thereby causing continuous, mutually variable movement in the machine device of a first part and a second part which are co-axial,
the first and second parts being in operational co-operation with a rotary main drive shaft which forms part of the controlling gear arrangement,
the main drive shaft being in operational gearwheel coupling with a first rotary sub-drive shaft for the first part and with a second rotary sub-drive shaft for the second part, respectively, and
the gearwheel coupling including therein co-operating elliptical gearwheels, and
the rotary main drive shaft is equipped with a fixedly attached elliptical gearwheel,
The invention relates also to a usage of such a controlling gear arrangement.
From the literature and as a product there is known a very large number of different types of displacement type machines, such as combustion engines, compressors and pumps. Such machines are, however, most often structured with two parallel or two eccentrically located axes of rotation.
Best known as combustion engine based on volumetric changes based on rotary geometries is the Wankel engine, and it is still being developed today. However, other internal combustion rotary engines based on geometrical volumetric changes have not found any commercial exploitation.
The known Wankel engine has only one rotor which rotates eccentrically in a stationary enclosing housing. In its first embodiments it was structured in such a way that what is the housing, in to-days well-known version, rotated about its own axis, implying that this first variant of the Wankel engine in reality appeared as a two-rotors engine.
However, the Wankel engine has not been a great commercial success, despite its capability of exhibiting high revolutions per time unit range and almost a vibration-less operation, small structural size and low weight. This is caused by substantial disadvantages such as relatively high manufacturing costs due to requirements related to fine polishing and coating of movement path of the inner circumference of the stator, significant sealing problems between stator and rotor, in particular towards the periphery. This is due to these sealing faces becoming extremely narrow, almost like a stripe, and where the angle of abutment is noticeably changed during rotation. Some of these problems have to a certain extent been solved from a technical view, but challenges related to geometry seem to be almost unsolvable. Inter alia, the combustion surface in the chambers between rotor and stator at the periphery becomes quite large, and the compression ratio is geometrically quite small. This results in the Wankel engine regrettably exhibiting low efficiency and a high fuel consumption.
In the literature and in numerous patent publications there are in addition found a substantial number of proposals related to machines having one or two rotors which exhibit eccentric axis of rotation.
The following patent publications are referred to as a representation of related prior art: US 2012/0080006-A1, U.S. Pat. No. 3,430,573-A1, US 2004/0187803-A1, WO 03/008764-A1, U.S. Pat. No. 5,622,149-A, GB 1021626-A, GB 1028098-A, U.S. Pat. No. 3,356,079-A and U.S. Pat. No. 3,112,062-A.
Pure displacement or expansion machines with rotary geometries appear most often as compressors for gases and to some extent as expansion machines for gases. Screw compressors with two parallel rotors and axes of rotation are to-day widely used, in particular for producing pressurized air. Within the field of expansion machines which convert pressure into mechanical power, there is present in particular lamellae based machines with an eccentric axis of rotation, and these are also used for tools powered by pressurized air.
Other structures of similar types appear as e.g. liquid pumps, being so-called displacement machines. Eccentric geometries are also often used in pumps, e.g. pumps for lubricants in car engines.